A bus is a public path for transmitting information between function components of a computer and is a transmission bundle that includes a conducting wire. Based on the category of information transmitted by the computer, buses of the computer may be classified into a data bus, an address bus, and a control bus, which are respectively used to transmit data, data addresses, and control signals. A bus is an internal structure and is a public path for the central processing unit (CPU), memory, input device, and output device to transfer information. Various components of a host are connected by the bus, and an external device is further connected to the bus using a corresponding interface circuit, thereby forming a computer hardware system.
The bandwidth size of a bus affects system service quality, and a decrease of the bus bandwidth may cause degradation of performance of a system. Because the bus is a connecting path of components of a host, once a physical fault (a breakpoint) occurs, catastrophic breakdown may occur in the system. To avoid occurrence of such an incident, reliability design is needed on the bus.
A hyper transport (HT) bus technology is a point-to-point connection technology which distinguishes four layers, namely, physical layer, data link layer, protocol layer, and transaction layer. Reliability design of the HT bus technology is mainly adding a data link layer cyclic redundancy check (CRC) code and performing data link layer check. A quantity of paths in the HT bus technology may have the following several choices, 32, 16, 8, 4, and 2. When a hard fault occurs in a bus path, correct running of a system may be achieved by manually setting bandwidth. This method needs human diagnosis and intervention, and does not have a function of automated diagnosis and processing. Then, although adjusting bandwidth may make a device run normally, a data transmission path cannot be dynamically selected in the method. If the hard fault occurs in a data transmission path that is being used, the system still cannot run correctly.
A bus self-healing technology is proposed in the prior art, where a physical path can be dynamically configured without the need of human intervention such that full bandwidth of a physical line decreases to ½ of the original in order to solve the problem that a physical fault occurs in a bus path.
In actual application of data transmission, because it is necessary to ensure that a data volume of a message unit at the data link layer is an integer multiple of a quantity of data transmission paths, when a fault occurs in a single path of a bus, if such a bus self-healing technology is used, the work of data transmission path modification will increase by multiples such that bandwidth at least decreases to half of the original, which severely affects system performance and wastes a large number of available paths.